Leaving aside whether anyone benefits from a pedantic insistence on defining ‘maintenance’ versus ‘improvements’ (I get it’s an important distinction, massive court cases have been won and lost on it - you’re not a property lawyer by any chance? 
), one of the points people are trying to make is that the fire safety regulations are inadequate and that the reason they are is because the people with power and money prefer them that way.
Whether the block complied with existing fire safety regulations is therefore only relevant in a very limited sense. Obviously, if it didn’t comply, that’s terrible. The problem people are concerned about does not go away if it turns out the building complied with every detail of fire safety regulations.
There is a history to this issue. I’ll just leave this here because it is about the most neutral and complete summary I’ve found:
http://www.bbc.co.uk/news/uk-politics-40302745
One of the reasons this fire is extremely political (note - not being politicised, it is a political issue right from the start) is that the UK had a fire in a tower block previously. It was a tragedy and a massive scandal, there was a major review and then basically nothing happened. Nothing substantive has been done to require any kind of upgrade in fire safety.
And now it has happened again, only with a great deal more loss of life.
Strangely enough, people are wondering why nothing was done and point the finger at the party that was in government through most of that time and which controls the local authority in which the building is located. Which just happens to be one of the richest places on Earth and certainly in the UK.
